docs: def as_unit(unit, precision=2, location='suffix'):
      """Convert value to unit.
  
      Parameters:
      -----------
      :param v: numerical value
      :param unit: string of unit
      :param precision: int
          decimal places to round to
      :param location:
          'prefix' or 'suffix' representing where the currency symbol falls
          relative to the value
      """
      if not isinstance(precision, Integral):
          raise TypeError("Precision must be an integer.")
  
      if location == 'prefix':
          formatter = partial(_format_numer, prefix=unit)
      elif location == 'suffix':
          formatter = partial(_format_numer, suffix=unit)
      else:
          raise ValueError("location must be either 'prefix' or 'suffix'.")
  
      return _surpress_formatting_errors(
          formatter("0.{}f".format(precision))
      )